Step 6: Checking for Treatments

A treated diamond is a diamond that has had its appearance altered by manmade means, usually to improve the diamonds color or clarity, or both. Treatments always affect the value of a diamond. In fact, laser-drilled and fracture-filled treated diamonds are valued at half the price of a natural untreated diamond. Other treatments will also affect the price.

There are a variety of treatments that can be carried out on a diamond, a small number of which can only be detected by a Gemological Laboratory; however, most can be detected very easily by our team of graders using a loupe and many years of experience. Two of the most common treatments that our graders come across are laser drilling and fracture drilling.

Laser Drilling – This is usually carried out on a diamond with black inclusions within the diamond. During this treatment the diamond is subjected to a laser which drills down to the unsightly inclusion and usually burns the inclusion out. If this does not get rid of the inclusion, the diamond is placed in a vacuum and acid is poured into the tiny hole in order to bleach the inclusion out. This process improves the clarity of the diamond, but can be detected by skilled diamond graders quite easily. (Before and After Laser Drilling)

Fracture Filling – This treatment is usually carried out on diamonds with surface-reaching inclusions, these are known as fractures. Again the diamond is placed into a vacuum and acid is poured into the fracture, bleaching the surface inclusion. From here glass is drawn into the fracture to fill the gap. This process improves the clarity of the diamond, but the treatment can easily be detected by skilled diamond graders.